半腱肌再生影响ACL重建后肌肉对膝关节负荷的特异性贡献
简介
该研究纳入18例ACLR术后2-4年患者（68%男性），通过MRI和三维运动分析（侧切动作），建立个性化肌骨模型，比较损伤形态模型（纳入ACLR相关腘绳肌改变，如半腱肌体积减小、肌腱参数调整，无再生者移除半腱肌）与健侧形态模型对膝关节负荷的影响。关键发现：损伤形态模型中，半腱肌对胫骨后向力的贡献显著降低（PMDI=47.5%，d=-1.16），而半膜肌（PM…
英文摘要
Hamstring tendon autograft is commonly used in anterior cruciate ligament reconstruction (ACLR). Harvesting the semitendinosus (ST) tendon induces morphological adaptations that may alter muscle and joint loading. Although ST tendon regeneration can occur, its post-ACLR function during dynamic tasks remains unclear. Eighteen participants (68 % male) who were 2-4 years post-ACLR underwent bilateral magnetic resonance imaging and three-dimensional motion analysis of sidestep cutting. Personalised musculoskeletal models were simulated under two conditions: an injured-morphology model incorporating MRI-derived ACLR-related hamstring alterations (reduced ST muscle volume, adjusted muscle-tendon parameters, and ST removal where regeneration was absent) and an uninjured-morphology model informed by contralateral hamstring morphology. Both models were driven using the same experimental kinematics and external loads acquired from the ACLR limb. From this motion analysis data, two sets of muscle-specific contributions to knee loading were quantified using sequentially linked static optimisation, followed by induced acceleration and then joint reaction analyses. Between-model differences were assessed using the Peak Model Difference Index (PMDI). Compared with the uninjured-morphology-model, the injured-morphology-model had reduced ST contribution to posterior knee force (PMDI = 47.5 %, d = -1.16), but increased semimembranosus (PMDI = 5.6 %, d = 0.95) and biceps femoris long head (BFLH) contributions (PMDI = 13.6 %, d = 0.72). These between-model differences were amplified in participants without ST tendon regeneration (e.g., semimembranosus (PMDI = 8.9 %, d = 1.55) and BFLH (PMDI = 14.5 %, d = 0.88)) compared with participants with ST regeneration (e.g., semimembranosus (PMDI = 1.8 %, d = 0.38) and BFLH (PMDI = 12.0 %, d = 0.76)). Persistent impairment of ST function post-ACLR results in compensatory redistribution of hamstring contributions to knee-joint loading during a challenging dynamic motor task, particularly when tendon regeneration does not occur. Results underscore the mechanical importance of ST integrity for balanced hamstring load sharing.